Reading through the white-paper, singleClicked and doubleClicked are subsections in zimletPanelItem. This would lead one to believe they could use them in the xml definition like this:

<zimletPanelItem label="My Label" icon="LabelIcon">
    <toolTipText>Description Here</toolTipText>
        <canvas type="window" width="400" height="600" />
        <actionURL method="get" target="" />
This is not the case. If I do this and single click on the Zimlet in the sidebar, nothing happens. Do I really have to use JavaScript to get this to work? (And, if so, does someone have a simple example)